10 June 2014
Fig. 1
The young star cluster NGC 3590
Credit: ESO/G. Beccari
Open star clusters are groups of stars loosely bound by the force of gravity. An open cluster may contain up to a few thousand stars. The stars of an open cluster form inside the same nebula, around the same period of time. Most open clusters are located within the disc of our Galaxy, the Milky Way, and, therefore, they are also known as galactic clusters. They generally consist of young stars, some of which are massive, hot and very luminous.
Fig. 1 is an exquisite image of the small open cluster NGC 3590. It was obtained by the 2.2-meter telescope at the European Southern Observatory’s La Silla Observatory in Chile. These brilliant stars shine in front of magnificent nebulae, dark clouds of cosmic dust and colorful clouds of glowing gas. This small stellar system gives astronomers clues about the birth and evolution of stars, as well as giving hints about the spiral structure of our Galaxy.
NGC 3590 is located about 7,500 light years away from Earth. It is visible in the sky among the stars of the constellation of Carina, The Ship’s Keel. Its stars are very young, by cosmic standards, estimated to be only 35 million years old.
Interestingly, NGC 3590 lies in the largest single segment of one of the Milky Way’s spiral arms: the Carina spiral feature.
The Milky Way’s spiral arms are huge curving streams of nebulae and stars, twirling out from the galactic core. Each of the four main spiral arms of the Galaxy is named after the constellations in which it is most remarkable. The Carina spiral feature is visible as a patch of sky densely populated with stars, in the Carina-Sagittarius arm. By studying young stars like those in NGC 3590, it is possible to find the distances to the different parts of this spiral arm, revealing more detail about its structure.
References
ESO Website
Wikipedia
Aymen Mohamed Ibrahem
Senior Astronomy Specialist